ri{EciiMTATioN or MoisTUiiE. :-^;09 



Mean amount of iwedpiiation of moialun, a» rain and incUed snow, for each month in the year. 



Name of statinii. 



Fort IJamlnll, Dak 



l-'ort I'ifirc, Dak 



Fort Abcrcroiubie, Dak 

 Fort Laiiunii", Wyo 



I 



0.40 

 0.50 



0. .■)•> 



0. Gl 



0.42 

 1.18 

 0.G6 

 0. 4G 



^ 



0.99 

 0.46 

 1.03 

 0.84 



•c 



P. 



<1 



S 



1. 10 2. 07 

 1. 63 I 2. 10 

 1. 82 1. 82 

 1. 06 3. 74 



2.30 

 0.48 

 2.18 

 1.90 



1.76 

 1.18 

 3.01 

 1.63 



a 



2.56 

 l.GG 

 2.30 

 1.37 



CO 



2.43 

 1.29 

 1.07 

 1.17 



1.09 

 1.08 

 1.30 

 0.97 



0.41 

 1.39 

 0.90 

 0.84 



0.30 

 0.47 

 0.64 

 0.57 



Mean amount of precipitation of moisture, as rain and melted snow, for the season and the whole year. 



Natno of Btatioii. 



Fort Eandall, Dak 



Fort Pierre, Dak 



Fort Abcrcrombio, Dak . 



Fort Laraiuie, Wjo 



Cboyeuue, Wyo 



FortBuford, Dak 





C 



a 



s 



V 



s 



o. 





CO 



93 



4.76 



6.64 



4.28 



3.32 



4.67 



7.49 



5.C4 



4.90 



3.11 



5.56 





6.49 





Tear. 



3.90 



1.21 



3.76 



2.15 



3.36 



1.82 



2.98 



1.64 



1.98 



0.37 



16.51 

 13.51 

 17.34 

 15.16 

 10.02 

 11.75 



Extent of 

 series. 



Years. Mo, 



8 

 1 

 6 

 12 

 4 

 8 



Date. 



Begiiinuig. End. 



1857 

 1855 

 1860 

 1840 

 1871 

 1867 



1867 

 1857 

 1867 

 1864 

 1875 

 1874 



It will be noticed from a comparison of the above tables that the 

 rain-fall for the whole Upper Missouri region follows the same general law, 

 being greatest in the spring and summer months, from May to September, 

 and least in autumn and winter, coinciding with the observations made in 

 the Black Hills the past season. The season of 1875 was remarkably wet 

 generally throughout the United States; At Cheyenne and North Platte, 

 on the Union Pacific, 220 miles south of the Black Hills, the rain-fall was 

 not above the average, but at Yankton and Bismarck, Dakota, situated 

 nearly an equal distance north and east, it was unusually great, as is shown 

 in the following table, compiled from the records of the Signal Service, 

 United States Army: 



